Cover operated switch



P 2, 1950 P. M. SANTULLO 2,522,053

COVER OPERATED swrrcu Filed June 16, 1947 2 Sheets-Sheet 1 MM 6W Sept.12, 1950 P. M. SANTULLO 3 COVER OPERATED swrrcu Filed June 16, 1947 2Sheets-Sheet 2 /& I 3

Patented Sept. 12, 1950 UNITED STAT ES PATENT OFFICE f oovEn OPERATEDswrrcn Pompeo M. Santullo, Newark, N. J.- 1 Application June 1-6, 1947,Serial No. 754,901"

' This invention relates. to an electrical cutout and alarm device forfurnaces and the like, which burn a gaseous fuel or a fuel from which a,combustible gas is likely to accumulate in the flues thereof.

'In furnaces as gas burning furnaces, there exists the likelihood thatunburned gas may accumulate in the lines due to the failure of the pilotor other igniter, and such'accumulated gas 'may later become ignitedcausing an explosion in the furnace and fluesj After the initial burningof such gases the fire may remain in the flues due to the gas beingforced through the combustion chamber into the-flues by the forceddraught blower. This burning of the gases in the fines results in damageto the flues and furnace and any v adjacent material.

It is an object of this invention to provide an "automatic switch fordisconnecting the blower motor and sounding an alarm when gases areignited in the fines. Flues of this type of furnace are frequentlyprovided with a blow-out pipe and cover to permit the escape of suchignited gases and it is an object of this invention to utilize theblow-out pipe cover as an operator for a switch to disconnect the blowermotor and connectan electric alarm circuit. 2

Another object of this invention is to provide a device of the kind tobe more particularly attached to the blow-out covers of furnacespresently installed, with little or no modifications necessary to thefurnaceor fiues. While provided primarily as an attachment, the devicemay as readily be built into the furnace and flue constructionspresently in progress.

A further object of this invention is to provide a switch connectedselectively with either the blower motor or alarm. In normaloperationthe switch will complete the blower motor circuit and after ablow-out will complete the alarm circuit while breaking the motorcircuit. While the device is so constructed to automatically move theswitch in one direction, it may be manually reset after such automaticoperation.

With the above and other objects in view, my invention consists in thearrangement, combination and details of construction disclosed in thedrawings and specification, and then more particularly pointed out inthe appended claim.

In the drawings,

Figure 1 is a side elevation of the electrical cutout and alarm deviceas attached to the blowout pipe of a furnace.

Figure 2 is a top plan view of the switch and switch operator,

1 Claim. (o1; 200-44) Figure 3 is a longitudinal section taken on theline 3-3 of Figure 2,

Figure 4 is a. transverse section taken on the line 4-4 of Figure 3,

Figure 5 is a fragmentary side elevation, partly in section, of theswitch removed from the device, Figure 6 is a diagrammatic Wiringdiagram.

Referring to the drawings, the numeral l9 designates generally a;furnace for burninggas, having a blower H driven by an electric motor I2, and having flues [4. connected to the upper end of the combustionchamber, to a chimney [5. The flue [4 includes a. vertical tube It, anda horizontal tube H. The horizontal tube It is connected to the verticaltube 16 intermediate its length and communicates at one end with thechimney l5, and is open at the other end.

The open end of the horizontal tube. II is closed with a movable coverE8. The horizontal flue H is known as the blow-out pipe of the furnace.

In the use of gas furnaces when the pilot lights have becomeextinguished, combustible gases frequently accumulate in the fines abovethe combustion chamber. These combustible gases in the fines may becomeignited through the subsequent lighting of the pilot light, or a sparkor ther applied heat to the fiues. Such ignition of these combustiblegases results in an explosion in the flues so the cover I8 is maderemovable to provide an exhaust for the exploding gases, to preventdamage to the fiues and to the furnace.

While the gases may accumulate in the fines due to their own weight, theblowers of the furnace move the gases more quickly into the fines. It isan object of this invention to provide a means for turning off theblower motor l2 and sounding an alarm when the explosion of gases in thefiues occurs. The alarm and cut-off device 20, constructed according toan embodiment of this invention, comprises a switch 2| in a housing 22fixed on the blow-out pipe [1.

The switch 2| is operated in one direction by movement of the blow-outcover 18 for shutting off the motor I2 of the blower and for completingthe circuit to an alarm 24, The housing 22 is rectangular in shape andopen at the top, as indicated by the numeral 25. The housing 22 is fixedto the free end of the blow-out pipe l1. One leaf of a hinge 26 is fixedto the outer end of the housing 22 by a rivet 2'! or other suitablefastening devices. The other leaf 28 of the hinge 26 is fixed to thecover I8. The hinge leaves are connected together by a pintle 29engaging through the barrels thereof.

An upwardly extending lever 30 is fixed to the blow-out cover l8 andextends upwardly into the housing 22. The double throw switch 2| isfixed to brackets 3| which are in turn fixed to the lower wall 32 of thehousing 22. The switch 2| is formed with an operating handle 33. Thehandle 33 is biased in both directions for completing a circuit throughthe pairs of contacts at each end of the switch 2|, The handle 33 isformed with an opening 34 near the upper end.

A rod 35 is pivotally connected to the upper end of the lever 39 by apivot pin 35, and loosely engages through the opening 34 of the handle33. The end of the rod 35 which engages through the handle 33 is reducedin size to provide a shoulder 3! intermediate the length of the rod 35.

A spring 38 is coiled about the reduced end of the rod 35 and iscompressible between the handle 33 and the shoulder 31; Such aconnection Drovides a lost motion connection between the cover I8 andthe handle 33 for moving the handle in one direction upon movement ofthe cover, and

the spring 38 constantly urges the cover Is to its normally closedposition.

For resetting the switch 2|, a reset rod 39 is pivotally carried by thehandle 33. The reset rod 39 is pivotally connected between ears 40intermediate the length of the handle 33, by a --l the hinge pin 29, Theupper end of the lever 30 is then moved rearwardly and as the spring 38is compressed the handle 33 of the switch 2| is moved to its rearposition. In the rear position of the handle 33, the circuit to themotor I2 is broken and the electric circuit to the alarm 24 iscompleted. When the switch 2| is reset by the movement of the switch 33to its original position, the alarm circuit is broken and the motorcircuit re-connected. The spring 38 is normally slightly compressed withthe switch 2| in the motor circuit position. When the handle 33 is inthe position for closing the circuit to the alarm, there still remainssome tension on the spring 38 for urging the cover I8 back to the closedposition.

I do not mean to confine myself to the exact' details of constructionherein disclosed, but claim all variations falling within the purview ofthe appended claim, a 1

What I claim is:

, Switch operating mechanism for a safety system for a. furnace having ablower motor, a blowout pipe, a pivoted cover therefor, and a doublethrow switch closing a blower motor circuit in one position thereof andopening said motor circuit and closingan alarm circuit in anotherposition thereof; comprising a housing for mounting on the blow-out pipeadjacent the pivoted cover and engageable over the switch, a leverrockably carried by said housing and having one end adapted forconnection to the pivoted cover, a rockable handle having one endadapted for connection to the switch, an opening formed through theother end f said handle, an actuating rod pivotally connected at one endthereof to the other end of said lever, a portion of reduced thicknessformed on the other end of said rod slidably extending through saidhandle opening, a coil spring member disposed about said portion of saidrod and bearing against said handle, and a reset rod extending slidablythrough a wall of said housing and having the inner end thereofpivotally connected to said handle. 1

POMPEO M. SANTULLO.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 978,849 Collier Dec. 20, 19101,564,207 Cloud Dec. 8, 1925 1,582,064 Maddox Apr. 27, 1926 1,886,854Vogt Nov. 8, 1932 2,111,431 Lum Mar. 15, 1938 2,469,082 Scanlon May 3,1949

